1. Field of the Invention
The present invention relates to a video apparatus and a video processing method.
2. Description of the Related Art
Heretofore, there have been known video apparatus for switching between different video processing processes to display a video image depending on the type of video signal included in an input signal (e.g., see JP-A No. 10-333627). FIG. 1 shows in block form a general arrangement of a related video apparatus. The related video apparatus is supplied with an RGB signal as an input signal that includes three image signals, i.e., R (red), G (green), and B (blue) signals, and two synchronizing signals, i.e., a horizontal synchronizing signal and a vertical synchronizing signal.
As shown in FIG. 1, the related video apparatus has synchronizing separator 10, synchronizing signal detector 200, CPU 300, data saver 40, A/D converter 50, resolution converter 600, video output unit 70, and video output device 80.
Synchronizing separator 10 separates an RGB signal input from a personal computer or the like into a video signal and a synchronizing signal, outputs the video signal to AND converter 50 and the synchronizing signal to synchronizing signal detector 200.
Synchronizing signal detector 200 has horizontal/vertical frequency detector 21, total vertical line number detector 22, synchronizing polarity detector 23, synchronizing pattern detector 24, and scanning pattern detector 25.
Horizontal/vertical frequency detector 21 detects a horizontal synchronizing frequency and a vertical synchronizing frequency from the synchronizing signal, and sends the horizontal synchronizing frequency and the vertical synchronizing frequency which are detected to CPU 300.
Total vertical line number detector 22 detects the total number of vertical lines of the input signal from the synchronizing signal, and sends the detected total number of vertical lines to CPU 300.
Synchronizing polarity detector 23 detects the synchronizing polarities (positive or negative) of a horizontal synchronizing signal and a vertical synchronizing signal, respectively, from the synchronizing signal, and sends the detected synchronizing polarities to CPU 300.
Synchronizing pattern detector 24 detects a synchronizing pattern from the synchronizing signal, and sends the detected synchronizing pattern to CPU 300. There are four synchronizing patterns, i.e., “Sep”, “Mix”, “G-Sync”, and “Tri”.
The synchronizing pattern “Sep” is a pattern in which a horizontal synchronizing signal and a vertical synchronizing signal are input separately from a video signal. According to the synchronizing pattern “Sep”, five signal lines are required to receive input signals, i.e., two synchronizing signals and three image signals including R, G, B signals.
The synchronizing pattern “Mix” is a pattern in which a single synchronizing signal comprising a mixture of horizontal and vertical synchronizing signals is input separately from a video signal. According to the synchronizing pattern “Mix”, four signal lines are required to receive input signals.
The synchronizing pattern “G-Sync” is a pattern in which a synchronizing signal mixed with a G signal is input. According to the synchronizing pattern “G-Sync”, three signal lines are required to receive three image signals including R, G, B signals.
The synchronizing pattern “Tri” is a pattern classified as a type of “G-Sync” in which a synchronizing signal is of three values. According to the synchronizing pattern “Tri”, three signal lines are required to receive three image signals including R, G, B signals as with the synchronizing pattern “G-Sync”.
Scanning pattern detector 25 detects a scanning pattern (Interlace or Non-Interlace) from the synchronizing signal, and sends the detected scanning pattern to CPU 300.
Data saver 40 saves data necessary for performing a video processing process depending on the detected results from synchronizing signal detector 200. CPU 300 reads data depending on the detected results from synchronizing signal detector 200, from data saver 40.
Data saver 40 also saves a horizontal resolution and a vertical resolution of a video signal which are estimated based on the detected results from synchronizing signal detector 200. Furthermore, data saver 40 saves setting data for storing a video signal of the estimated horizontal resolution and the estimated vertical resolution into video memory 62 at predetermined horizontal and vertical writing intervals, and for reading the video signal from the video memory 62 at a predetermined reading interval.
For example, setting data to be set in resolution converter 600 represent the horizontal and vertical writing intervals and the reading interval at which the video signal is stored in and read from video memory 62, and horizontal/vertical resolution conversion ratios of horizontal/vertical resolution converter 61 for storing the video signal into video memory 62 at the horizontal and vertical writing intervals. Setting data to be set in A/D converter 50 represent the number of samples of video signal that are to be stored into video memory 62 at the horizontal and vertical writing intervals.
CPU 300 determines a general memory area of data saver 40 based on the total number of vertical lines of the input signal, and also determines a detailed memory area of data saver 40 based on the horizontal synchronizing frequency of the horizontal synchronizing signal. Since the data saved in the memory area are data depending on the vertical resolution of the video signals, CPU 300 reads the saved data.
As described above, the memory area of data saver 40 is divided based on the total number of vertical lines and the horizontal synchronizing frequency. However, the memory area may be divided into a more detailed area using the vertical synchronizing frequency, the synchronizing polarities, the synchronizing pattern, and the scanning pattern as additional information.
CPU 300 sets the number of samples read from data saver 40 in A/D converter 50 in order to write a video signal into video memory 62 at the horizontal/vertical writing intervals read from data saver 40.
CPU 300 also sets the horizontal/vertical writing intervals and the reading interval read from data saver 40 in horizontal/vertical resolution converter 61 of resolution converter 600. Furthermore, CPU 300 sets the horizontal/vertical resolution conversion ratios read from data saver 40 in horizontal/vertical resolution converter 61 in order to write a video signal into video memory 62 at the horizontal/vertical writing intervals that have been set.
A/D converter 50 samples a video signal according to the number of samples set by CPU 300, converts the sampled video signal into a digital video signal, and outputs the digital video signal to resolution converter 600.
Resolution converter 600 has horizontal/vertical resolution converter 61 and video memory 62.
Horizontal/vertical resolution converter 61 converts the horizontal/vertical resolutions of the video signal at the horizontal/vertical resolution conversion ratios set by CPU 300, and writes and saves the resolution-converted video signal in video memory 62. The time at which to read the video signal from video memory 62 is adjusted by CPU 300 depending on the time at which a video image is output from video output device 80.
When the time comes at which to read the video signal from video memory 62, horizontal/vertical resolution converter 61 reads the video signal from video memory 62 at the reading interval set by CPU 300. The video signal read from video memory 62 is output from horizontal/vertical resolution converter 61 to video output unit 70.
Video output unit 70 outputs a video image based on the video signal output from resolution converter 600, to video output device 80. Video output device 80 projects the video image output from video output unit 70 onto a screen with light emitted from a projection light source (not shown).
A video processing performed by the related video apparatus shown in FIG. 1 will be described below with reference to FIG. 2.
As shown in FIG. 2, synchronizing signal detector 200 sends at least the total number of vertical lines and a horizontal synchronizing frequency which have been detected thereby, to CPU 300, in step 801.
In step 802, CPU 300 reads data depending on the vertical resolution of the video signal from data saver 40, using at least the total number of vertical lines and the horizontal synchronizing frequency which have been sent from synchronizing signal detector 200. Specifically, if the vertical resolution of the video signal is 768, then CPU 300 reads an estimated horizontal resolution of 1024 and an estimated vertical resolution of 768, and also reads set data in conformity with the estimated horizontal resolution of 1024 and the estimated vertical resolution of 768.
In step 803, CPU 300 sets the number of samples that have been read as set data from data saver 40, in A/D converter 50. In step 804, CPU 300 sets the horizontal/vertical writing intervals, the reading interval, and the horizontal/vertical resolution conversion ratios which have been read as set data from data saver 40, in horizontal/vertical resolution converter 61.
Subsequently, A/D converter 50 samples the video signal according to the number of samples set by CPU 300, and converts the sampled video signal into a digital video signal. Horizontal/vertical resolution converter 61 converts the horizontal/vertical resolutions of the video signal at the horizontal/vertical resolution conversion ratios set by CPU 300, and saves the resolution-converted video signal in video memory 62. Thereafter, the video signal stored in video memory 62 is read at a time adjusted by CPU 300, and a video image based on the video signal is output from video output unit 70 to video output device 80.
An exemplary problem of the conventional apparatus and methods is that some video signals have the same vertical resolution, but have different horizontal resolutions. For example, some video signals have a common vertical resolution of 768, but have various horizontal resolutions of 1024, 1224, 1280, and 1360. Since it is generally difficult to distinguish between video signals which have the same vertical resolution, but have different horizontal resolutions, the operator is required to manually switch between such video signals. To handle such a plurality of video signals, data saver 40 should have data saving areas for saving signals of the different horizontal resolutions.
The related video apparatus shown in FIG. 1 is unable to appropriately process video signals which have the same vertical resolution, but have different horizontal resolutions.
For example, if a video signal has a horizontal resolution of 1360 and a vertical resolution of 768, then since CPU 300 sets the number of samples for A/D converter 50 so that it can process a video signal having a horizontal resolution of 1024 and a vertical resolution of 768, the sampling process performed by A/D converter 50 reduces an amount of video signal data. The lack of video signal data results in a different aspect ratio, making it impossible to display a proper video image. Therefore, the operator must manually reselect data from data saver 40 while viewing the displayed image. In addition, data saver 40 is required to have an increased storage capacity for handling video signals which have the same vertical resolution, but have different horizontal resolutions.